Electrical switching apparatus for telephone systems.



B. E. CLEMENT.

ELECTRICAL swrrcnme APPARATUS FOR TELEPHONE SYSTEMS.

APPLICATION FILED JAN. 6, 1906. RENEWED D110. 31, 1910. 1,029,591,Patented June 18,1912.

6 SHEETS-'SHEET 1.

hwsozo E. E. CLEMENT.

ELECTRICAL SWITCHING APPARATUS FOR TELEPHONE SYSTEMS.

APPLICATION FILED JAN. 6} 1906. RENEWED DEC. 31, 1910.

1,029,591. Patented June 18,1912.

6 SHEETS-SHEET 2.

2 7 SJ n wanton Witnesses E. E. CLEMENT.

ELECTRICAL SWITCHING APPARATUS FOR TELEPHONE SYSTEMS.

APPLICATION FILED JAN. s, 1906. RENEWED DBO. 31, 1910.

1,029,591, Patented June 18,1912.

6 SHEETS-SHEET 3.

vv vvvvvvrr animator E. E. CLEMENT. ELECTRICAL SWITCHING APPARATUS FORTELEPHONE SYSTEMS.

APPLICATION FILED JAN. 6, 1906. RENEWED DEC. 31, 1910.

1,029,591 Patented June 18,1912.

6 SHEETS-SHEET 4.

E. E. CLEMENT.

ELECTRICAL SWITCHING APPARATUS FOR TELEPHONE SYSTEMS.

APPLICATION FILED JAN. a, 1906. RENEWED DEO.31,1910.

1,029,591; Patented June 18, 1912.

v 6 SHEETSSHBET 5.

Patented June 18, 1912 6 SHEETS-SHEE 6 For E. E. CLEMENT.

GTRIGAL SWITGHKNG APPARATUS FOR TELEPHONE SYSTEMS.

ELE

GATION TILED JAN 6, '916. RENEWED DEC. 31, 1910 'UNITED STATES PATENTOFFICE.

EDNARD E. CLEMENT. OF WASHINGTON. DISTRICT OF COLUMBIA.

ELECTRICAL SWITCHING APPARATUS FOR TELEPHONE SYSTEMS.

Application filed January 6, 1906. Serial No. 294.97?

T 0 all whom it may concern:

Be it known that I. Enwann E. CLEMENT. a citizen of the United States.residing at \Vashington, in the District of Columbia. have inventedcertain new and useful Tm provements in Electrical Switching Apparatusfor Telephone Systems, of which the following is a specification.reference being bad therein to the accompanying drawings.

My invention relates to electrical switching apparatus for telephonesystems and has for its object the improvement of such apparatus in bothconstruction and arrangement. as will appear from the followingdescription.

My invention relates particularly to ap paratus of that class commonlyknown as automatic, wherein switching devices are mechanically actuatedto interconne t (il'- cults, their operation being ordinarily controlledelectrically frol'n a distance.

In some cases. and in some systems which I have designated assemi-automatic those machine or automatic switching devices are combinedwith manual apparatus. in other cases or systems the general equipmentis all manual, with auxiliary devi es of an automatic nature.

My present invention is applicable to any system in which automatic ornun-hintswitching devices are to be employed. whether full automatic.semi-automatic. or manual with automatic branches or aux1liaries.

The gist of the invention lie in the design of what I may call theswitch unit. that is to say. the individual mechanism which forms theunit whose lnllltll ilk'lllllill makes up a system or exchange. and theuse in corn nection with this switch unit of what I shall hereinaftercall unit sections. each made up of a frame work or casing adapted toreceive and hold a certain, number of the switch units constituting agroup. each group being in itself a self-contained and complete subdivided. section of an ext-hang equi 'wment.

Perhaps the most important feature of nrv design and of the invention isthe capability of apparatus thus made to be built up by aggregating unitswitches in a section. and

then by aggregating sections. each complete in itself, to form acomplete cfv hci'i le or switching outfitof any desired size andcapacity. So far as. I know this has never i before been acpomplished.Heretofore. a considerable part of telephone engineering Specificationof Letters Patent.

Patented J unc 18.1912.

Renewed December 31. 1910. Serial No. 80027 work has consisted in thedcsign of cxchange ctpiipments. that is to sa v in the preparation fplans and specifications for the b ilding and installation of ompletesuit hlurards or automatic outfits. with the auxiliarv apparatus andlittings appertaining thcrcto. It has been necessary to design andinstall each plant as a whole. its so-callcd ultimate capacity beinglimited. with thc prcscni equipment anything dcsircd within the limit.The principal reason for this in manual switchboard installations hasbeen that in n urlv all cases they have emplovi-[l multiplc swit hbours. but in all installzr lions an additional reason has bccn found in thcdisregard of all dl)tli\'i it)ll in the general arrangement. cable andwiring pla .\ccordin;r to my present invention I h .ide switch unitswhich arc uniform. anti each of which is intcrclmng ealdc with everyither unit. This permits great economy in manufacture. I mount the partsof each unit n a pert'w-tl tlat skeleton frame. and provide a unitsection or cabinet into which the frames can he slid edgewise. (pen theback of each unit section or *abinet l mount contact strips of theswitches. these being straight strips containing preferably one hundredsets of springs. with platinum points for all contacts included intalking circuits. The switch frames sdde into the cabinets from thefront. and are provided with guides so that they will auton'mticallalinc themselves with the contact strips when in place. I make theframes of the switches. the unit sections or cabinets. and the contactstrips all of metal. so that ex cept for the nece insulation on tileswitch num net:--. and between the. contact springs n the strips. tlicrcis absolutely nothing combustible in any part of the outfit. All wireconnections are made to the contact strips on the back and outsidethereof. the same being inclosed by metal covers titted on the backs ofthe cabinets. the fronts of which are also fitted with'covers which mabe either all of metal or metal frames with glass pan ls The unitsectnm.--: or cabinets being? all the same. another great economy inmanufa ture brought about. and instead (it ha 'iz'rg to design completeframeworks and in closulcfor switching outfits. it i ni rciy ncct saryto pile up unit sect ion cabinets in any desired manner to form therequired ag qgiegatiou of switches for any given change. Thisarrangement is exceedingly flexible, and as the design of the backcovers of the cabinets leaves the same open at top and bottom, thewiring and cables can be led up and down without any special provisionbeing made therefor, no matter what the combination. Thus, sections maybe piled up to form banks of any desired height and of any length, orthey may be piled to formbays or aisles, or irregularly around the sidesof a room. or in any other desired manner. The usual provision will ofcourse have to be made in every case for cables, which may be theemployment of a false floor upon which the switch units are placed.

In order to render any aggregation of units complete, I provide top andbase sec-' tions which are standard units in themselves, adapted toregister with any unit sections or cabinets, and with the covers then ofback and front.

It will be perceived from this brief statementthat I have produced whatmay be called a" system of mechanical construction and arrangement ofautomatic switches which is very flexible, highly etlicient. and

adapted to produce the greatest economy in manufacture.

In conjunction with my switches as such I employ relays, for controllingand dirt-cling the various switching operations, and these relays. whichin lliQttlStlYtS form no part of the present invention, are separatelymount ed on racks or frames, and incloeed in dust and nioi turwproot'eases. uitablc provision being made for the inelosure and protection olthe wire and cabl s in the Ellulll,

it is her fore po-silue in the przr'tictof my some high potentialdischargrr or alien current getting pa t. the proteitive devices of anexchange. the damage don in my system would be l mited strictly to tinparticular unit. section in which ihc burn-out takes place.

lv believe l am the first to ilc ign a system outfit of apparatus whi hcan be asscnr bled and operated in the manner stated, and l thcrclorcdesire my cl-inns t; be given a broad ctmstruction.

My invention illustrated in the ac ompanying drawings. in a hich-- Figme1 is a side \l w of a switch unit and its contact hank. Fig. 2 is anedge vii-w of the same. part of the switch frame being broken away toshow lhe nuignet mountings. Fig. 3 is a detail hgure presenting a sideview of the magnet mountings, armature,

and working pawls. Fig. 4 is a face view of the left'hand verticalmember in Fig. 3. Fig. 5 is an end view of the contact bank and theswitch spindle with the operating studs thereon. Fig. 6 is a detailfigure showing a portion of the switch spindle, together with the fixeddctent which holds the same against rotation during its verticalmovement. Fig. 7 is a side view similar to Fi 1, showing the manner ofmounting the switch and its bank in the unit section frame or cabinet.Fig. 8 is a face view of a unit section, with five switch units mountedthere in. Fig. 9 is an end view of the same. Fig. 10 is a rear view of aportion of the same. Fig. 11 a top plan view of the samef Fig. 12 is afront view of a cabinet formed by aggregating four unit sections withbases and tops. Fig. 13 is an end view of the same. Fig. let is a detailperspective view of a pair of fastening devices for securing the unitsections together.

Fig. 1 shows a unit switch. with its contact bank, removed from theframe or cabi net. This switch is marked Z, and the colitact bank, whichis manufactured and cone pletely assembled apart from the switch. markedZ. The switch comprises a flat.

( pen frame, 2*, having pro ectmg ends,

and a central lateral displaced. portion, ,2, forming one side and theends of a rec tangle in which I locate the o iicrating magnets, K. L, W.The corners of the rectangle' are preferably connected with the cornersof the frame by the web 2 which merge into a flange, 2 which extendsentirely around the frame and serve... a double purpose; it no. nlystilfens and strcnglhcn.-- the structure, but the end flanges slide ingrooves in the unit section cabinet and ther by support the switch.

Extending longitudinally of the frame. and parallel to the long inanbersthereof. is the tubular operating spindle. sliding upon end studs 2'",.2, which are rigidly secured to the end pieces .2. .2 respectively. Thespindle. 2. is broken in the middle to receive the ratchet member, whichhas a. vertical ratchet. 2 with eleven annular teeth, and a rotartratchet. 2 with straight teeth around its periphery. These ratchets arecut in a solid piece of brass or other.suitable metal, which hasprojecting end studs, 2?". 2*. brazed into the dividednds of the tube,The studs or pos s. a, .2 are shown of considerable length, and in fact1 find it advlsable to make them as long as possible. allowing for thelength of the ratchet body, and the necessary movement of the tube orspindle. The end studs are of course spaced so as to permit free up andspi .dle, and their length, by giving an ex; tended bearing Within thetube, prevents *n as well as rotary movement. of the binding orfriction, and also adds stiffness and insures good alinement. making oneof the end studs of sufficient length and diameter as respects'thespindle to give the requisite rigidity and provide the proper bearingsurfaces for the spindle. only one such end stud may be used.

Inside the rectangle formed by the frame member. 2, frames. W, Z and it.The first of these forms a part of the magnetic circuit of the releasemagnet W. and serves also to sup port the release bar, to, having thepawls or fingers. or. 105. In addition I fasten to this member. \V',- aknife edge detent'bar, to, best shown in Figs. 4 and .6. and concealedby the member. 10, in Fig. 1. This knife edge is engaged by some one ofthe teeth of the rotary ratchet, 2'. after it has been turned and thespindle is being raised, and 1 the adjustment. of the parts is such thatthe spindle cannot be turned after it has stepped up vertically to thefirst contact position. Because of lack of space, Fig. 1 is slightlyshortened, and is shown with the first vertical step of the spindle atonce bringing a stud into engagement with the first contact in itsseries, but attention is called to the fact that in describing thecirci-iit'arrangen1ent.'I have stated that this may andin the circuitshown should require two steps. hence the arrangement in Fig. l may bechanged Without altering the mechanism. the primary or initial positionof the studs being entirely a matter of adjustment. to determine whetherone. two or more steps shall be taken before any of them can reach thecontacts.

In Fig. 3 I have shown a detail of the.

three soft iron frame pieces. with the magnet cores and windingsremoved. also with the release lever taken otf by loosening the screw.10'. which with the fixed pivot point. [172. support it in position. Thevertical ratchet. .2 of the spindle is engaged by a pawl, Z pivoted tothe end of the armature. P. of the vertical magnet. L. This armature ispivoted between ears. 7'. formed on the frame. I. and normally restsagainst the adjustable bat-k stop, I. which is tapped into an extensionon the frame. The toe of the pawl (Xttlitls out through an opening. Z".cut. into the plate. ll". just above the top of the knife edge. r. Theheel (-f the pawl is pulled back toward the pivot point of the armaturelever by means of a spring. 7".

Tn order to assist gravity in pulling down the armature lever. 7 andretracting the pawl when the magnet L is detinergized. i provid a coiledspring on a spindle having an end key. the spindle i-ng parallel withthe pivot of the armature. and the key resting in either one of the twodiametral slots in the ears of the and serving when twisted to wind upthe frame.

and spring extendl l t j ratchet. z

are secured three soft iron;

to the j spring so as to adjust it to any desired strength. The opening.Z". not only guides but limits the movement of the pawl. l", whichnormally rests against its lower edge and is thereby turned upon itspivot so as to be withdrawn from engagement with the when the armature.1 drops back. \Vhen the armature is attracted, on the other hand. thepawl is lifted off the edge of the opening. and the spring. Z pulls backits heel. throwing its toe forward through the opening. so that it willengage with and move the ratchet one step. It can not go farther thanthis one step. by reason of the toe striking against the upper edge ofthe opening. Z which thus becomes the vertical limiting stop.

The frame. I: is three-sided. and carries between its left-hand ends thearmature. It. pivoted at its lower edge (looking down on Fig. 3) betweenthe members. It", It. Secured to the lower part of the armature. nearthe pivot point. is a righthand lever armJr which normally lies awayfrom the observer looking at Fig. 3. withdrawing the pawl. k through theopening. 7v. shown in Figs. 3 and 4. Vl'hen the magnet K is energized.the armature. is rocked on its pivots to the right in Fig. 3. asindicated by the arrow: the lever. 7c, then comes forward toward theobserver. (or to the right in Fig. l) and pushes the toe of the pawl.in, against a tooth of the rotary ratchet, .2 so as to turn the same.The armature. it normally rests against an adjustable set-screw, tappedinto the extension, is. on the arm, It": and the armature is held inthis position by means of the coiled retracting spring. 7c. secured atits lower end to the member, la", and at its upper end to a key. is.similar to that shown at Z for magnet. L. It will thus be perceived thatthe walls of the opening. Z serve as limiting stops for the rotary pawl.Zr. just the same as those of the opening. I. serve as limiting stopsfor the pawl. F. The iron member. V. in which these openings are formed.is punched and formed up so that it is always the same andinterchangeable: moreover. its relation with the other members. 1 and Z.is the same in all switches. by reason of the method of attach ing theseparts to the frame. They all tit into the rectangular space. andregister with each other. being secured to the frame y suitable screwsor other fastening devices passing through the frame. It will be observed. after studying Figs. 1. 2. 3. 4 and 6. that the magnets. K. L.and each with its ircn frame and the parts attached thereto.

can be separately removedfrom the frame. 2'-" 'The magnets and theirworking parts are made up and assembled separately. and applied to theframe as units. which tends to economy and uniformity in manufacture.Whereas each of the magnets, K andL, has

two spools, the release magnet \V has only one spool, its work beingslight, and thh parts which it moves being very light. When the magnet Kis energized one or more times it steps around the spindle, in a rotarydirection, and the return of the spindle is prevented by the detentpawl. 11-. on the pivot lever, 11:. When the magnet b is energized oneor more times it lifts the spindle vertically, and the same is preventedfrom falling by the pawl. w which engages the vertical ratchet-,2. Assoon as the vertical pawl comes into play the rotary pawl loses itsfunction, since the ratchet wheel, a, then engages the knife edge, 21;,and cannot turn 1 This which occurs when the proper circuits are a,which it will be observed are inserted in closed as I have alreadypointed out in my description of the diagram. This lever, 1 has aprojecting arm, 2.0 which is shown on the side toward the observerin'Fig. 'l. and on the side away from the observer in Fig. 7. The leverbeing pivoted on the soft iron frame. 7 and the pivot screw and point.1r. a being preferably of iron, the mag netic circuit is completedthrough the frame member, the ore of magnet through the arm. to, and thebody of the lever, 11 Then the magnet energized the arm. 1r. is drawn into its pole, and in order to 'l acili tate this operation l prefer tocurve the end of the arm somewhat, to form a hook p ity surrounding thepole of the-magnet. \Yhen the arm is attracted to the pole, the lever.11:. is rocked on the pivots, w", w and the toes of the two detents. in,70 are removed from engagement with the ratchets, .2. the latter eingthen released so that pring pressure or gravity or both may return thespindle to its initial position as shown in the figures. Thereturn ofthe spindle. in arotary direction to its initial position is accomplishcd by means of a coiled spring sur-- rounding the spindle, at 2one end of this spring being tapped to the spindle and the other to thelever, ra fwhose end is fitted t and travels in a longitudinal slot cutin the inner face of the frame. 2'. The initial position of the spindledetermined and fixed by means of the stop lever, 2 This lever is carriedrigidly on the spindle in a yoke. 2 which may be adjusted and thenlocked upon the spindle. A

The contact strip, Z, is made and assembled separately from the switch,andiq adapted to be secured to the unit ection cabinet so that when theswitch is placed -therein it will register with the strip and may be 2secured together by screws, 2 and clamping between them one hundred setsof securcdthereto. The strip consists t essentially of two channeledside bars,

line or trunk circuit. These one hundred sets are dividedintoten groups,which Ihave indicated in Fig. 1 by the letters 2", 2 2 Below each groupI leave a space, 5 2, z, 2, 1', 2 2 2, z and 2 Opposite these spaces, Isecure upon the spindle radial studs, 2' 2* 2", 2, .2, 2' .2, .2 2". and.2 These studs are set helically around the spindle, as clearlyindicated in Fig. .7. to which I will now refer in order to mak clearthe construction of the contact strip. Each set of springs comprises apair of outside line springs, 2 .2. a pair ol trunk springs, 2', .2 anda pair of test springs, .2, Interposed between these springs are stripsof in snlation, preferably. of hard rubber, and the whole is joinedtogether by the side bars,

.2 through the medium of the screws,

the spaces between the groups of springs. All the springs, 5 thrtmgh thelength of the entire strip are coni iectcd together, and may in fact bemerely projecting comb teeth on a common plate or strip. All ofthesprings, 5. are individual springs, that is each pair forms outgoingline or trunk terminals. All of the springs. 2', and all of the springs2 are joined together throughout the entire strip, and therefore thesealso may merely be teeth on a comb. The springs, .2 however, areindividual, each being associated with a pair of springs, s, so thatwhen the sprin a is tested it indicates the con dition of the circuitconnected to the other twonamed. One of the studs being brought in linewith one of the groups of contacts by means of rotary movement ofthe'spindb .2, is then moved up vertically by the corre' spondingmovement of the spindle. passing between one pair after another of thecontacts r as it pa. ses. 1 might dispense with the common contact set,and make the studs carry the test current as wipers, but I prefer tohave all the contacts fixed and no cir uit carried through the spindleor other moving parts. As the stud passes upward between these testcontacts, it also spreads apart the which move with the inner -trunkcircuit correspondingly.

The frame 00 has the ends of its transverse members a received intom0rtises formed in solid end pieces fitted between the side bars a -s2of the contact strips. and is secured in this position by screws passingthrough lugs Contact springs, each set associated with a formed on theinner faces of the end menr and bridging across: each pair which areindicated in Figs. 1 and the letter a.

The end members themselves, 2 are partly cut. away at z to I will dfol-iii shoulders which rest against the inner faces of thecontactstrips and the solid end pieces thereof. so to afford a positiveand invariable means of elinement for the switch ports with respect tothe Contact. strip.

Referrii i now to Figs. 8 to 14 inclusive, t be my unit section cabinet.In Fig". this shown with five switches Z slid into gzlace. looking atthem from the front. N one of the contact strips are shown which belongto these switches. The frame l. of the unit section is formed of fourvertical channel irons, two at each end, set per-- ellcl to ouch other,transversely connected across the top and bottom at each end by an angleiron 7')", and longitudinally connected i'ront and'bucir by the upperand lower'anglc irons 72 A skeleton frame or cage is .hus formed. whichI c ose on the top, bottom and by means of sheet iron. On the ends thisis slnnvn as a plain facing p hold in place by being passed between theinbefore they are secured "e and channel 11 i i prorribly do byriveting. ittom closures. however, have top and another function, whichis to support and ii'al' tingle irons on the back of the ser e as guidesfor the switches Z. As

Each is pro he. with a series of trans- ;e grooves 71 formed in it byrolls or dit It convenient method of forn'iing this intiterml with thegrooves in it is to pass up of the required width between two llors orcylinders, one of which has transverse g1 coves and the other hascorrespond.

in; transverse projections to register with the 'rooves as the rolls arerotated. These may then be cut into the desired len; h, and secured inplace as shown in the figures by bolting or riveting the ends, preferuhly the latter.-

The contact strips Z are secured verticz lly upon the upper and lowerlongitudi frame, as shownin Fig. 10, and as indicated in plan in Fig.11. The simplestway oi" securing these in place is by the screws passing1 through the upper. and lower end pieces I and tapped into the feces ofthe angle irons.

These strips being; thus fixed upon the frame, support upon'their rearfeces all the circuit wires leading-to their coi'itects, that is, allthe wiring of the SW1tCt1S,- exc pt only the wires leadin to the three317.11 7 1 r: i p n s b s K. L end ll, .VlHCi] are suitably oisposeuupon the frame of each switch, nnnate contacts a COOI)I9 UH' tiXedco-ntacts (see Figs. 1 and 10 strips bein all in position, the ppcrstinportions of each switch are introduced i'roi ill and it, these arelettered V the front by sliding them into the grooves 79 in the top andbottom plates 19*. As they ere slid into place they automatically alinethemselves with the contact strips, by the ends of the end flanges 2entering the mortises in the blocks 2 of the strips, and the shoulderscoming against the inner faces of the strips. Screws 2 and 2 are thenturned home in the lugs 2- and 2, so as (4) hold the parts in position.It will be apparent from this description that the magnets K L and XVare brought into connect-ion with their respective circuit wires by themere act of inserting theswitch parts inthe frame; and the entireswitch'body is therefore instantly detached, and all the switch bodiesare absolutely interchangeable. In manufacturing and assembling theyare-all 'set up and tested in a common frame and with a common set ofcontacts, in addition. to which the other contact strips are all made inthe same templet, which itself is made from the common set of contactswith which the switch bodies are tested, {hence therecan be novariation, but all parts are standard.

Referring to Figs. 12, 13 and 14,1 here show the method of assembling myunit sections into a complete cabinet. In Figs. 12 and '13 I give ufront and a side elevation, respectively, of a cabinet formed byaggregating four unit sections, two bases and two tops. Each of the.unit sections is shown at 1. Each of the tops is shown at N,'and eachof the bases at N. It will be observed from Fig. 13 that the top N andbase N are back of the frame, and along their rear edges fitted with 2Lstiffening angle plate 72*. The sheet. iron end cover 7) is alsoextended back to the rear edge of the angle iron p and across the wholerear faceof the section,

from one angle plate 7." to the other is eX- tended a. straight piece ofsheetiron 29, secured by detachable devioessuch as screws 2 It will beperceived. that in the rear of each frame there an. inclosed chamberwhich I have marked 7) in Fig. 11., open at the top and bottom, andpermitting the passage of circuit conductors to the strips. The top Nand the base N are made of sufiicien" depth to cover the top and bottom,respectively, of these chambers, and since the base hollow, being itselfformed of sheet nets! i estiiieniug' frame, the cables may he town from.the strips and through the we to any desired point. The bacloof the forthis purpose is also fitted with u. removable cover 72 in order to carrythe weight which is placed upon it, each base sent an ornamentalappearance.

section N is formed with a skeleton frame having vertical members a, twoat each end, registering with and of the same shape as the. channelirons p of the unit sections. These end members are united top andbottom by'longitudinal members a which may advantageously be angles, andtransversely they are united at their front ends by their angle bases n-n*,the latter of which is extended out front and rear to give a widefooting for the base. Upon this skeleton frame is fitted the sheet ironcover a, having an ornamental front, and end pieces, with a removableback. This cover as well as all of the other parts of the cabinet may bepainted or enameled, or galvanized or otherwise treated to preserve andornament the metal. p

The top N is made in any suitable or preferred manner from sheet metal,with accurately fitted edges so that it Willtake over the top of theupper unit section I all around, and close the same-in a substantiallydust and moisture-proof manner.

Each section P of the cabinet is closed in front by a metal cover 22,fitted, if desired, with a glass panel 79". I have shown only one ofthese covers, and it should be under stood that they may be merely ofiron without panels, if desired. Glass used in such relations is veryliable to breakage, and the panels are large enough to be quiteexpensive,hence I prefer plain iron covers, except where it is desiredto have the cabinIet 1prelfivt) shown covers secured at top and bottomby 'screws 7), upon loosening which the same may be removed by means ofthe handle 7). The edges of. this cover may rest all around upon a stripof felt, to exclude dust and moisture, and the same material may, infact, be used elsewhere in the joints, if desired,'for the same purpose.

It remains to describe the method of fastening the unit sectionstogether to form the cabinet. For this purpose I employ corner blocks N-N, shown. in F g. .l-l. flhcse arev .of proper shape-to have theirbodies slid into the channel in the end-members 7) of the frames. Asclearly shown in 12. there are four of llltsr members f unit section P,and four for ea h h: The top N has none. but is itled 'n'i sockets toreceive those of the sect upon which it may be-placed in buile up acabinet, the base is fir sci (1m n a the floor, and fastened f ing downthe end slri four corner blocks sticking .ip, i tion P which comes nextin order 1.-,. pla upon the base so that these blocks the channels ofits end members 7;. top of thissection there are four i, I blockssticking up, and if another section 3:

added, it is similarly placed upon the first one, so that these blockswill enter its end members, and so on, until the case is finally placedupon the top section P, with the ing it in place. Where two verticalsets are to be piled up, as shown in Fig. 12, the two bases N are firstlaid down and secured, and then the blocks N'-'-N of the bases whichcome together receive a bolt shown in dotted lines in Fig. 12, at Thesetwo bolts confine the bases together, and when the sections P are putupon them,, they confine these sections together also at the bottom. Theblocks N"N ont-he twosections at their meeting places are then boltedtogether in the same manner, and so on up, each protruding pair ofblocks being bolted together before the next pair of sections P is putin place; so that when the two tops N are finally superposed on thecabinet, the whole is firmly tied together and cannot be disturbedexcept by vertically lifting the members apart, which their' town weightand the weight of their contents sufficiently provides against. In orderto insure great steadiness,

same trnnlcor line circuit. Instead of putt ng these side by side I mayput them vertieally above each other forconvenience in wiring themultiples; and I maymake the frames of other material than iron; butsuch changes, and many details which will at once occur to those skilledin the art after reading j t'rnis comprising a this specification, I donot describe herein,

5 and do not specifically claim, Wishing it understoodnevertheless thatthey are included withinihe scope of my invention, and while genericallycovered herein, may be specifi cally covered in other cases.

2 Having thus described. my invention what l "witch for-automatictelephone sys- ,JY'ISlDg a flat open frame having projecting ends, astraightstrip of contacts extending parallel to the body of said framebetween the ends thereof, an operating mem mounted in the framelongitudinally and electromagnetic means'for actuatihi; aperating mcmbc1.11110. sub tantially as r :ribed.

.\ switch for autmnatic telephone systlal .fame having proofcontacts'secured he:

are those which contain multiples fthev I claimand desire to secure byLetters Pat-' ml is:

srm'f and parallel with the strip of con-' tro mounted upon the nallelt5 the body of the blocks thereof entering its sockets and'holdframe. anope 'ating member for said contacts extending parallel thereto andcarried upon the frame. and electro-magnets for actuating said memberalso mounted within and upon the frame, substantially as described.

3. switch for automatic telephone s\ tcms comprising a flat open frame,,stitfcning flanges upon said frame.'a contact strip connected to saidframe, an operating member for the contact stri carried in the frame,and electromagnetic actuating means for said member supported in andupon the frame, substantially as described.

4. A. switch for automatic telephtme systems comprising a flat openframe, a straight strip of contacts mounted lengthwise of the f -ame, anoperating member mounted in the frame parallel thereto. andelectro-magnetie actuating means for the operating member also mountedin and upon the frame. the dimensions and arrangement of all the'partsbeing such as to constitute a structure hav ing relatively greaterlength than thickness. substai'itially as dcscri bed.

3. switch ft automatictelephone systems comprising a flat frame ofconsiderable length relativeto its thiclcm-ss, with stiffening flangesand projecting ends, a straight strip of contacts and an operatingmember therefor secured to the frame within the ends, andelectromagnetic actuating means for the ope 'ating member carried uponand within an intermediate portion of the frame, all the parts being soproportioned and arranged as to lie substantially within the.

thicltrwss of the frame, substantialh as described.

t. switch for automatic telephone systems having a frame composed oflongitudinal body members and transverse .irojccting' end members. withstiffening flanges all lying between the same plai'ies. and of smallthick ness relatively to the end of the frame together with contacts, anoperating member therefor, and cleotro-magnet ic actuating means. allsecured upon and lying substantially within the thickness of the frame,substantially as described.

7. A switch for automatic telephone systems comprising a. long tlatframe. with operating parts all mounted upon and within the thickness ofthe frame. and c ntacts onstituting line terminals arranged in astraight line and in general parallelism with the major dimension of thefra he. nbstau tiall v a-.- described.

8. switch for automatic telephon sr tents comprising a flat and openfram with extended longitudinal members and trans verse ends. a strip ofcontacts mounted to lie parallel with the longitudinal members andlwtv'i-cn the end an op rating spindle cooperating with said contactsand mounted upon the frame between the ends i'lii't 'tlf,

and actuating means for said spindle also mounted on the frame,substantially as d'e scribed.

9. A switch for automatic, telephone sy tems comprising a flat fra-tueraving ex tended longitudinal members and transverse ends, contactssecured to said frame. anda tubular operating spindle working upon studssecured to theends thereof, substan tially as described.

10. A switch for automatic telephone sys tems comprising a frame.movable contact members, fixed terminal contacts in longi tudinal order.and a tubular operating spindle working upon studs in the frame,substantiall f as described. 1 r 11'. A switch for automatic telephonesystems comprising an elongated frame carrying an Operating memberextended in the direction of its lengtln-and electromagnetic actuatingmeans therefor intermediate of its ends, a straight supporting stripdetachably secured at its ends to the ends of the frame, and a pluralityof contacts for the operating member supported in said strip.substantially as described.

12. A switchfor automatic telephone systems comprising an elongatedframe, operating parts mounted thereon. to work on the long axisthereof, a straight line unitary .mounting strip in substantialparallelisn'i with the said long axis of the frame, a plu rality ofcontacts secured upon said strip, and detachable connections between theframe and the contact strip, substantially as described.

13. A switch for automatic telephone systems con'iprising an elongatedflat frame having an open central portion, and operating parts mountedthereon in the opening approximately within the thickness of the. frame.substantially as described.

14. A switch for automatic telcplione systems comprising an elongatedframe. ontacts in straight line parallel relation thereto, terminalstuds secured upon said frame, and a'tubular spindle lying paral letwith and cooperating with the contacts and working upon said studs.substantially as described.

15. A switch for automatic telephone tems comprising a Hat elongatedfrai having a wide central portion and reduced ends, a spindle.cxtendingin the dire tion of its length, and the central portion open, withelectromagnetic actuating means for the working parts mounted upon theframe within said central portion substantially as described.

16. switch for autonnitlc telephone sys tents comprhing an elongatedframe, electro-magnetic actuating means mounted then-on, contacts thereo? supported in a straight line, in a fixed :l'iit and means fordeachahly securing fl of the frame to the contact strip with theactuating parts in operatii e relation with said contacts, substantiallyas described.

17. A switch for automatic telephone systems comprising a support, astraight bank of contacts rigidly mounted as a unit on said support, andan elongated switch frame carrying operating parts extending along anaxis parallel to said bank, and adapted to be detachably secured uponsaid contact bank, substantially as described.

18. A switch structure for automatic telephone systems comprising asupport, a straight bank or strip of contacts rigidly mounted as a unitupon said support, a frame carrying parts extended along. the length ofthe frame, adapted to cooperate with said contacts, and means fordetachably securing said'frame upon said bank with the cooperating partsin working parallcl relation with the contacts, substantially asdescribed.

19. A switch structure for automatic telephone systems comprising asupport. a straight bank or strip of contacts rigidly carried upon saidsupport, a switch frame carrying working parts extending in parallelismto said bank, guiding means on the support over which the switch frameis adapted to travel and means to secure the switch frame upon and inoperative relation to said guiding means and thereby .to ad just it onthe support with its parts in operative relation to the contacts,substantially as described.

20. In an automatic telephone system. a switch system comprising asupport, separable units carried on the support, each unit having aplurality of sets of contacts carried upon it, and a'switch framecarrying operating parts, adapted to be detachably connected with andcarried on each unit in operative relation with its contacts,substantially as described.

21. Automatic switching apparatus for telephone'systems comprising asupport or frame structure in separable interchangeable units eachcomplete in itself, a plurality of individual switch banks mounted inparallelism upon each unit, and a plurality of associatedinterchangeable switch frames carrying working parts detachably securedin operative relation to the respective banks, substantially asdescribed.

Automatic switching apparatus for telephone systems comprising separablegroups of fixed banks and detachable individual switches, each groupmounted. and

secured together as a unit and all groupsor units being interchangeable,substantially as described.

23. Automatic switching apparatus for telephone systems comprising asupporting structure formed of an agprcgaicn of separable units. eachunit composed of an inclosure complete in itself, and a complete groupof switches containing related multi ples, mounted in each supportingunit, sub stantially as described.

24. Automatic switching apparatus for telephone systems comprising asupporting structure formed of an aggregation of separable units, eachunit complete in itself and all units interchangeable, together with aplurality of switches containing related multiples mounted dctachably ineach unit, substantially as described.

Automatic switching apparatus for telephone systems composed of abuilt-up aggregation of separable and interchangeable units, eachcomposed of a complete and symmetricalgroup of fixed banks anddetachable interchangeable switches, and-a containing case,substantially as described.

26'. In automatic switching apparatus for telephone exchan es, asupporting structure comprising a plurality of unit cabinets havingmetal frames and mounting strips, said units being interlocking andseparable with out the use of tools, a set of contact banks or stripscarried on the mounting strips in each unit. and a corresponding offrames with operating parts detachably connected to said banks andinclosed within-the unit cabinets, substantially as described.

- '27. Switching apparatus. for telephone exchanges comprising anaggregation of separable unit cabinets having means to pass cable fromeach unit to and through other units without interference, and with acomplete unit group of switches containing multiples of the same groupof circuits, mounted and inclosed within each unit cabinet,substantially as described.

- 28. In a telephone exchange system, switching apparatus composed of aplurality of separable and interchangeable selfcontained units, eachunit comprising a complete and symmetrical group of fixed banks anddetachable switches sembled and connected together for switching adefinite number of circuits, substantially as described.

29. In a telephone exchange system, an automatic switch out-fitcomprising a frame. inclosing walls for saidframe, mounting stripssecured upon said frame, switch banks secured in a homogeneous groupupon said mounting strips, and frames carrying the working parts of theswitches secured upon said banks, and a front plate or panel forinclosing the frame'and contacts, substantially as described.

30. Telephone exchange switching apparatus built up of standardinterchangeable units each comprising a frame formed of metal strips orangle bars with sheet metal inclosing walls, and a group of automaticswitches mounted within and upon said fra ne, substantially asdescribed.

closed and located in operative relation to the switch contacts,substantially as described.

.32. Automatic switching apparatus for telephone systems composed of abuilt-up aggregation of separable and interchangeable units, eachcomposed of a complete and symmetrical group of relatively fixed bankswith separable and interchangeable switches, substantially as described.

33. Automatic switching apparatus for telephone systems composed of abuilt-up aggregation of relatively fixed but separable andinterchangeable groups of separable and interchangeable switches, eachgroup complete for a predetermined number of lines, and each switchcomposed of separable and interchangeable parts, substantially asdescribed.

34. Astep by step selector switch comprising bank contacts, a spindleand Wipers carried thereon, together with actuating mechanism for thespindle adapted to rot-ate the same and also-to reciprocate it in avertical direction, a rotary ratchet carried on the spindle, and a knifeedge carried on a fixed portion of the switch body normally out ofcontact with said ratchet but adapted to engage the same when thespindle is reciprocated'and thereby prevent rotation of the spindleexcept in one position.

35. A step by step selector switch having contacts, wipers, a rotaryratchet, fixed and movable means for actuating and holding said ratchet,said fixed means being normally disengaged from the ratchet, and

means for. causing engagement of the ratchet by said fixed holdin means.

In testimony whereof I a x my signature in presence of two witnesses.

EDWARD E. CLEMENT.

Witnesses.

E. EDMONSTON, J r., JAs. ONEAL.

Copies of this patent may be obtained for live cents each, by addressingthe Commissioner '0": Patents,

Washington, D. C."

